Hollow projectile



T. E. MURRAY, JR., AND]. B. MURRAY HOLLOW PROJECTILE.

APPLICATION FILED JULY 15. 1918.

v Patented May 13, 1919.

under pressure.

. UNITED STATES PATENT OFFICE.

THOMAS E. MURRAY, JR., AND JOSEPH IIYIIURRAY, F BROOKLYN, NEW YORK.

HOLLOW PROJECTILE.

Specification of Letters Patent. Patented May 13, 1919.

Application filed July 15, 1913. Serial No. 244,937.

' provement in Hollow Projectiles, of which the following is a specification.

The invention is a hollow projectile of the type thrown by trench mortars, and more especially designed to hold a lethal gas The invention consists in the construction whereby the projectile is made of a pura'lity of parts, which by electrical means are rendered integral and gas tight at their places of union, so that leakage of the dangerous gas is prevented. In the accompanying drawings Figure 1 is a section of our shell on the line 1, 1 of Fig.2. Fig. 2 is a section on the line 2, 2 of Fig. 1. Fig. 3 is an end View of the fuse-receiving plug showing the rib to which the booster tube is electrically welded. Similar letters of reference indicatelike parts.

The shell body is produced by the process which is set forth in our copending application Serial No. 244,935 filed July 15, 1918.

. structure, much difliculty has been found in shell.

That is to say, briefly, from a plate of thin or sheet metal we produce by pressing in suitable dies, a unit section which represents one-half of the shell divided on a longitudinal plane. A plurality of these sections are all alike, and hence interchangeable, so that any two of them when placed with their edges in registry will form a complete Two sections A, B are shown thus placed inFig. 1. The edges of said sections are then integrally and electrically united by currents of great strength and of verybrief duration, whereby the metal of one section is rendered so completely and integrally coherent with the metal of the other section as that the strength at the joint is as great as if not greater than the metal elsewhere: or in other Words, the shell becomes substantially of one piece, everywhere of homogeneous metal. I

In shells hitherto devised for containing a lethal gas under pressure and in which there are joints between the parts of the making these joints gas tight. Various expedients, such as packing said joints with cement, have been tried. So also attempts have been made to effect a satisfactory union by the blow-pipe flame, and by seat-. lng one part within another, or making one part overlap the other and then forcing them together under heavy mechanical or hydraulic pressure. We are not aware that any certainly successful result has been obtained. Ordinary welding or blow-pipe welding involves the useof fluxes which remain in and more or less impair the joints;

so also it is never certain that the union is perfectly made, for .there is always danger of burning the thin 'metal, or of irregular or imperfect adhesion between the contacting surfaces. So far as we are advised, no shells have been yet produced competent to withstand a hydrostatic pressure of over-1200 pounds to the square inch. Furthermore, in gas shells the pressure of the gas is variable. If introduced, as is now usual, at 40 pounds to the square inch, it may be increased to double that amountif the shell be sufliciently heated, as may happen if exposed in the sun in summer. It is unnecessary to explain why va gas shell liable to leakage of its lethal contents is quite as dangerous to friend as to foe.

VVe'have discovered that a shell joint electrically Welded b currents of great volume and of very brie duration is absolutely impervious to gas within, and even far beyond, any utilizable limit of pressure. We have tested such joints at pressures of 4000 pounds to the square inch and under water without producing any evidence of leakage. In fact in hand grenades made in two sections of thin sheet metal electrically welded together as described, we have used gas ressures suflicient to start deformation '0 the sections without any leakage showing itself. Gas shells are usually made with a tubular projection C at one end which is threaded to receive the fuse-holding metal plug D. To this plug the booster tube E has to be united, the said tube extending into the body of the shell containing the gas under pressure, and itself containing the blowing charge of explosive which after ignition by the fuse determines the rupture of the shell and the liberation of the contained gas.

The attachment of the tube E to the plu D has been a serious source of trouble, an it is here especially that the embedding of the end of the tube in a groove in the plug with subsequent rolling or pressing of the jection C, tube and plug are inserted into.

and removed from the shell at the. same time.

it is to be noted that in our construction both of the critical joints, namely, between the shell sections A, B and between booster tube E and plug D, are absolutely gas tight, and that these are all the joints there are, excepting the one between the fuse plug D and projection C. At this joint relative detachability of the parts is required in order that the loaded booster tube with the fuse plug may be inserted after the shell is gas charged. 7.

The term lethal gas used in the claims means any gas which on contact with the human body or when taken into the lungs is irritating, corrosive, poisonous, or in any other way injurious to health or destructive to life.

We claim:

,1. A hollow projectile for containing, under pressure, a lethal gas, comprising a plurality of sections electrically rendered impervious to said gas at their places of union. 1

2. A hollow projectile for containing under pressure a lethal gas, comprising a plurality of parts electrically and integrally united and thereby rendered, within a eelected pressure limit, gas-tight at their places of union. 3. A hollow projectile for containing under pressure a' lethal gas, comprising a pluralityof interchangeable sections of sheet metal with their ed s in registering contact and electrically an integrally umted and thereby rendered, within a selected pressure limit, gas-tight at their joints.-

' 4. A hollow projectile for containing gas under pressure, comprising two interchangeab'lealongitudinally divided sections of struck up sheet metal integrally and electrically welded at their mgistering edges, an integral tubular rojectionon one end of said projectile, a use carrier in said projection, and a booster tube integrall and electrically butt-welded to the inner ace of said fuse carrier.

5. A hollow projectile for containing gas under pressure, comprising two interchangeablelongitudinally divided sections of struck up sheet metal integrally and electrically THOMAS E. MURRAY, JR. JOSEPH B. MURRAY.

Witnesses:

GERTRUDE T. Pon'rnn, MAY T. MCGARRY. 

